Printing plate location and affixing means



.AJD- 28, 1958 v G. A. MOGGRIDGE I .2,821,026

PRINTING PLATE LOCATION AND AFFIXING MEANS Filed June 24, 1955 PRITING PLATE LOCATION AND AFFIXING lVIEANS George Arthur Moggridge, St. Catherines, Ontario, Canada Application June 24, 1955, Seal No. 517,820

5 Claims. (Cl. i3-184.5)

This invention relates to printing apparatus, and more particularly to a means for enabling quick, accurate and eiective mounting and positioning of exible printing plates upon plate cylinders or plate beds.

Flexible plastic and rubber plates are widely used in the printing art, and many methods of securing these plates to the plate cylinders or plate beds have been proposed. One of the most satisfactory securing methods has been the use of a two-sided sheet of adhesive which is Czitpplied first to rthe plate, and then to the cylinder or The use of such a sheet provides a rigid, lirm and positive bond between plate and bed or cylinder, but in practice, considerable diiculty has arisen in accurately positioning or registering the plate on the bed or cylinder when such a two-sided adhesive sheet is used.

In practice, the registration of such plates has hereto fore been, to a large extent, a hit and miss proposition. The beds of cylinders are, as a rule, scored in l or 1" squares, and the plate, with adhesive backing applied, is applied to the cylinder or bed visually. Once the adhesive back touches the bed or cylinder, it is impossible to shift it even slightly, without distorting the plate, and if it is found that the plate thus visually applied is misaligned o1 misregistered, the plate must be removed and -reapp-lied. It will be appreciated that the proximity of the rst application to the desired register is lost upon its removal for the second application, and the problem is aggravated where more than one plate is used, especially where two or more colours are involved. This random placing of the plates and the time involved in registering and aligning is expensive since the presses are idle while the plates are being applied.

It is a principal object of this invention, therefore, t provide a means whereby a flexible plate having an adhesive backing may quickly and accurately be registered and positioned upon :the cylinder or bed.

It is a further object of this invention to provide such a means that will permit accurate prepositioning or registering of the plate upon the cylinder or bed.

It is another object to provide such a means of simple construction or application readily adaptable to all types of exible printing plates now in current use.

These and other advantageous objects will become apparent through a consideration of the following detailed description taken in conjunction with the attached drawings in which:

Figure 1 is a plan view showing a exible adhesive backed plate embodying my invention.

Figure 2 is a fragmentary, enlarged vertical cross-section of a portion of the plate shown in Figure 1, and

Figure 3 shows the plate of Figure l being registered or aligned upon a plate bed prior to application.

This invention consists broadly in the provision of a separate strip applied to the top, bottom or side edge of the plate, the adhesive backing then being applied to the plate and extending some distance beyond the plate and onto the separate strip, but not extending to the outerfUnid States Pate'fht" o 2,821,026 Patented Jan. 28, 1958 most edge of the strip. If a plate thus constructed is held at an angle to the cylinder or bed, the non-adhesive backed edge of the separate strip may be aligned and positioned precisely with respect to the scored lines or other positioning guides on the cylinder or bed and after this edge is positioned the plate may be aixedin the desired position rmly by swinging it about the edge of the separate strip and bringing the adhesive backing Von the plate into contact with the cylinder or bed.

In greater detail, and referring now to the drawings, and in particular to Figures 1 and 2 thereof, 1 represents a exible rubber or plastic printing plate, to the reverse side of which a double-faced adhesive sheet 3 has been applied. The dimensions of the adhesive sheet are identical to or very slight-ly' less than those of the plate with the exceptionk of the portion 3A which lextends beyond one edge of thel plate at the top, bottom or side thereof. In practice, a projection of M4" will be found to be adequate for the adhesive backing, and it will be appreciated that the edge of lthe plate beyond which this portion is to project, will be governed by the manner in which the form is to run, and will be chosen to best enable the operator to position the plate.

A separate strip 2 preferably of plastic Kor other exible nature is Ithen butted against the selecte-d edge of the plate, and brought in contact with the projecting portion of adhesive backing 3A. The strip is, as shown, the same length as or slightly shorter than the edge to which it is alixed, and may be of transparent plastic. This strip, for contrast with the cylinder or bed, may be coloured, and thus facilitate positioning with respect to the cylinder or bed. The width of the strip is largely a matter of preference, but in practice should be held to a minimum for most efficient results. Assuming that lthe `adhesive backing projects a `distance of 1A beyond the plate a strip of 1/2" width will be found to be satisfactory and a strip as narrow as could be used. Such strips would provide non-adhesive projections of 1/4," and M3 respectively which would in practice be suicient for the purposes hereinafter outlined. It will be appreciated that While a coloured transparent plastic strip has desirable features, the strip need not necessarily possess any of these qualities and substances other than plastic may be used, such as cardboard, but care must be taken to ensure that the material chosen is solvent repellent. The strip of course need not be coloured, nor transparent, and a non-exible material may also be substituted provided that it is not too wide, in this case the junction with the two-sided adhesive acting as a hinge.

A plate so equipped may be employed as illustrated in Figure 3. In Figure 3, 4 represents the printing chase or bed to which it is desired to ax the plate, and a scribed positioning line is shown as S. The plate 1 with projecting strip 2 atixed in the manner already outlined, is held at an angle to the chase, and the outer edge of the strip 2 is positioned with respect to the scribed positioning reference line 5. Since the plate is being held at an angle, only the edge of the strip 2 will come into contact with the bed or roll and since this edge has no adhesive backing, then it may be freely and minutely positioned with respect to the reference line 5. When the edge is in the required position, the thus aligned edge is maintained rigidly by hand and the plate swung down onto the bed or chase about the thus postioned edge and the adhesive backing thus firmly securing plate and bed together.

Because the use of this projecting strip permits the plate to be positioned before the adhesive touches the bed, the hit and miss practice which characterized former procedure is completely eliminated with a resultant saving in time and money.

When in this specification I use the expression exible 3 plate, I mean a plate of rubber, plastic or metal or a combination thereof whose Shore Vhardness-is less than 100 or a plate thin enough that though its Shore hardness is greater than 100 it may be bent.

,This iriven'tionfhas been described above in onel embodime'nLfindetail. 'It vis to bei understod,`hcwever, that the Vforegoingdescription'is offered/by Way of example only, andshould not be construed as a limitation of this my invention. YSuch embodiments of my invention as fall Within the scope and purview of the appended claims are to be considered as part of my invention.

What I claim as my invention is:

1. Meansfor enabling'the accurate location and afxing of exible adhesive backed printed plates .upon plate cylinders or beds, consisting of a strip abutting and alxed to one edge of the plate, said strip beingvlt to l" in width and having an adhesive backing on all but the outermost Ms" to 1A" thereof.

2. Means for enabling the accurate location and axing of flexible printing plates upon plate cylinders or beds '4' consisting of a double-faced adhesive sheet applied to the reverse face ofthe plate, saidrsheet being of substantially the same dimensions as the plate, but extending a kdistance beyond said plate along one edge thereof, an additional strip of greater width than said distance, and of length substantially equal to the length of the plate edge beyond which said sheet projects, f1 said additional strip being butted against the plate edge and being axed by a portion of its-lower-face to said projecting sheet. Y Y

3. Means as claimedin claim 2 wherein said sheet projects a distance of from 1/s" to 1/4" and said additional strip is from 1A" to 1/zfin width.

4. Means as claimedin claim3 wherein said additional strip is'formed Yof transparent plastic material.

5. Means as claimed in'claim 4 wherein said additional strip is formed of coloured, transparent plastic material.

References Cited in the tile of this patent UNITED STATES PATENTS p Daniels .f.. July 3, 195.1 

